Manhole extension



April 22, 1952 REDMAN 2,593,918

MANHOLE EXTENSION Filed Sept. 29, 1948 IN VEN TOR. HOWARD PEDMAN BY W 9 M42 Azfys.

Patented Apr. 22, 1952 1 UNITED STATES PATENT OFFICE MANHOLE EXTENSION Howard Bellman, Erlanger, Ky. Application September 29, 1948, Serial No. 51,661

2 Claims.

This invention relates to manholes and extensions therefor and more particularly relates to an adapter ring for extending a manhole cover support frame or head ring.

An object of this invention is to provide means for extending the elevation of a manhole cover without the necessity for destroying surrounding pavement.

Another object of this invention is to provide a manhole extension ring which can readily be added to a manhole head ring to raise the level of a manhole cover to the level of a pavement.

Another object of this invention is to provide means for anchoring a manhole adapter ring in a manhole head ring.

A further object of this invention is to provide a light weight manhole adapter ring and means for anchoring the adapter ring against turning and against tilting or cocking by overpassing traffic.

The above and other objects are attained by the means described herein and illustrated in the accompanying drawing in which:

Figure 1 is a fragmentary view, partly in crosssection, of a manhole and an adapter ring constructed in accordance with an embodiment of this invention;

Fig. 2 is a plan view of the adapter ring shown in Fig. l; and

Fig. 3 is a fragmentary sectional view along a line 33 in Fig. 2.

Briefly the present invention provides an adapter ring which can be positioned in a man hole head ring to raise the level of a manhole cover. When a new pavement is added on top of an old pavement, it is necessary to raise the level of manhole covers to bring them in alignment with the new pavement. The adapter ring of the present invention is adapted to rest on a cover seat of the manhole head ring and hold the manhole cover above the head ring and flush with the new pavement. Anchorage lugs project downwardly from the adapter ring below the cover seat of the manhole head ring. The lugs are bored to receive screws or pins, and the bores may be angled outwardly and upwardly so that as the screws or pins are turned into the ring against the lower surface of the head ring cover seat the adapter ring is pulled down tightly on the head ring. The adapter ring can fit on top of the head ring, and an outer circumferential surface of the adapter ring is provided with a plurality of spaced, substantially vertical slots or scallops into which paving material of the new road surface can penetrate to hold the adapter ring against turning.

The adapter ring is further provided with a central depression or cover seat for receiving a manhole cover. This application is a continuation in part of my application Ser. No. 677,317 filed June 17, 1946, now abandoned.

As illustrated in the drawings, an adapter ring constructed in accordance with this invention is indicated generally at Ill. The adapted ring It) fits on a cover seat I2 of a manhole head ring I3. As shown in Fig. 1, the manhole head ring may be of a conventional construction, and cover seat I2 is an annular ring integral with head ring I3 and extending inwardly therefrom. The upper edge of the head ring is flush with an original road surface I4. As road surface I4 becomes worn from the continuous pounding of heavy' traffic, modern practice is to renew the worn surface by the addition of a layer of some paving material such as black top or asphalt, indicated at I6, directly over the old pavement, the grade of the road being elevated to a degree equal to the thickness of the added paving material. The adapter ring Iil serves to hold a manhole cover I! flush with new surface layer I6. Ring I0 has an annular flange I8 disposed within the ring and at a level below the top surface thereof to form a seat for the cover I1. The depth to the seat may be substantially the same as that of the cover seat of manhole head ring I3 and the diameter may be the same so that the original manhole cover I1 may be used in the elevated manhole opening.

The bottom face I9 of the ring rests on head ring cover seat I2. Spaced above face I9 is an annular shoulder 2! which can rest on the rim of head ring I3. An upper annular rim 22 projects upwardly from upper annular shoulder 2| to the level of new pavement I6, and adapter cover seat I8 is formed inside rim 22.

In order to prevent turning of the adapter ring on its seat in the head ring, the outer surface of rim 22 is provided with a plurality of substantially vertical slots or scallops 23 into which paving material of new surface layer I6 penetrates to hold adapter ring IIl against turning.

In order that the adapter ring 9 may be secured against cocking or tilting by overpassing traffic, the ring In is provided with a plurality of lugs 24. Theselugs are uniformly spaced and extend downwardly from the inner face of cover seat portion of the ring to a point below head ring seat I2. As shown in Fig. 1, the lugs have upwardly and outwardly extending threaded bores 26 which receive retaining screws 21. The angle of these screws is such that as they are tightened, they bear on a lower surface of cover seat l2 pulling the adapter ring I I] firmly in position in head ring l3 and anchoring it against cocking or tilting.

The adapter ring of this invention may be formed as a single unitary casting. It can :be of reasonably light weight, for the retaining lugs are substantially lighter in weight than would be a continuous anchorage rim and the use of scallops 23 reduces the weight of rim 22. When an adapter ring 10 is to be attached to a head ring, it is simply positioned therein, and screws 21 are tightened to hold the ring in place. Then, when. new pavement surface layer It is added, the paving material naturally extends into scallops 23 to prevent the ring In from turning inside head ring l3.

The embodiment of the invention herein shown and described admits of modification without departing either from the spirit or the scope of the invention as set forth in the appended claims.

What is claimed is:

1. An adapter ring for manhole cover head rings of unitary cast structure provided with an inwardly directed seat flange comprising a manhole cover seat portion and a rim portion extending upwardly and outwardly from the seat portion to form a retaining wall for the cover and an annular inwardly extending shoulder forming a seat by which the adapter ring may be supported on the rim of the manhole head ring, the inner edge of the seat portion being provided with a plurality of spaced downwardly extending lugs provided with threaded holes the axes of which slope upwardly and outwardly of the lugs for receiving screws, the screws being disposed to bear against the under side of the seat flange of the head ring and draw the adapter ring down tightly on the head ring, the rim portion of said adapter ring being provided with a plurality of spaced vertically extending flutes on its outer surface adapted to receive surface paving material, whereby the ring is locked against turning in the rim of the supporting head ring.

2. In combination, a manhole head ring having a hollow body, an annular cover seat flange projecting inwardly from the hollow body, and a rim surounding said cover seat, said head ring being mounted in an opening in a main pavement, an adapter ring having an annular face resting on the cover seat, an annular shoulder resting on the rim of the head ring, and an annular shoulder within the adapter ring providing a seat to accommodate a manhole cover, said adapter ring including a plurality of anchorage lugs attached to the lower side of the adapter ring and extending below the head ring cover seat, said lugs being provided with threaded transverse openings, the axes of said openings extending upwardly and outwardly of the adapter ring, and screws in said openings, said screws bearing on the underside of the head ring cover seat flange to draw the adapter ring down tightly on the head ring, the rim of said adapter being provided with a plurality of spaced vertically extending flutes on its outer surface, and a secondary pavement above the main pavement and extending into the flutes of the adapter ring to locl; the adapter ring against turning in the headring.

, HOWARD REDMAN.

REFERENCES. omen The. following references are of record in. the

file of this patent:

7 UNITED STATES PATENTS Number- Sayles Nov. 18, 1947 

